The present invention relates to improved anti-static and fabric softening materials, and stabilized compositions containing same. More particularly, the invention encompasses conductive salts dispersed in a substantially water-insoluble quaternary ammonium or quaternary phosphonium compound. Improved liquid fabric softening and anti-static compositions stabilized with amides are also provided.
It has long been recognized that surface active agents, especially cationic materials such as the quaternary ammonium compounds, provide an advantageous softening and anti-static effect when applied to fabrics. Moreover, it has been suggested that various conductive salts should provide an anti-static benefit when applied to fabrics. However, it has been concluded that conductors such as the inorganic salts are not suitable for general use as anti-static agents on textiles, inasmuch as they are corrosive, abrasive, non-adhering or easily removed by water. In theory, however, electrically conductive salts should provide a mechanism whereby static electrical charges can be dissipated from fiber and fabric surfaces; see, for example, American Dyestuff Reporter, P405, June 21, 1954.
While the quaternary ammonium compounds commercially employed as softening agents are effective for this intended use, the anti-static properties of such materials are not optimum. This may be due to the highly localized attachment of the quaternary compounds to fabric surfaces which counteracts the inherent ability of these compounds to dissipate static electricity. Moreover, it is recognized that by raising the water concentration at a fiber/air interface, electrical charges can be more rapidly dissipated. When affixed to a fabric surface, the quaternary compounds do not provide the requisite charge mobility and/or hygroscopicity necessary for optimal anti-static performance.
A number of methods for providing improved fabric softening and anti-static compositions have been suggested. For example, U.S. Pat. No. 3,329,609 teaches the use of fluosilicic acid salts in combination with quaternary ammonium compounds. The efficacy of such compositions is taught to be caused by the polyvalent anionic character of the fluosilicic acid anion. While presumably effective for their intended use, the fluosilicate salts are derivatives of fluosilicic acid, which is toxic, corrosive, and extremely difficult to work with on a commercial scale.
U.S. Pat. No. 3,154,489 discloses the use of various polyvalent anionic materials in combination with quaternary ammonium compounds as fabric softeners.
The co-pending application of Morton, Ser. No. 335,194, filed Feb. 23, 1973, relates to the use of organic fatty acid derivatives in combination with various quaternary compounds as detergent-compatible fabric softening compositions. However, the Morton compositions do not contain metal salts dispersed throughout the insoluble phase comprising the quaternary compound in the manner disclosed hereinafter.
U.S. Pat. No. 3,719,613 discloses detergent compositions comprising metal salts of complex cyclic amines said to be useful as anti-static agents. However, the complex amine salts of this patent are not related to the standard quaternary ammonium compounds employed herein.
By the present invention there are provided improved fabric softening and anti-static compositions comprising an electrically conductive metal salt dispersed in a matrix comprising a substantially water-insoluble cationic quaternary compound. Such compositions are useful per se as softening and anti-static agents in the manner disclosed in the concurrently filed application of Montgomery, et al., Ser. No. 402,504, filed Oct. 1, 1973, incorporated herein by reference.
The present compositions can also be formulated as liquid fabric softeners having improved anti-static properties comprising a dispersion of the combined softening and anti-static agents herein in a liquid medium. However, stable liquid dispersions of quaternary compounds are difficult to prepare, and the presence of the electrically conductive salts herein poses additional stability problems when preparing such dispersions; see U.S. Pat. No. 3,591,405. It has now been found that amides can be used as stabilizing agents to provide stable, homogeneous dispersions of the improved softening and anti-static agents herein.
It is an object of the present invention to provide improved anti-static materials comprising an electrically conductive salt dispersed in a quaternary compound.
A second object herein is to provide improved fabric softening and anti-static compositions.
It is still a further object herein to provide improved fabric softening and anti-static compositions as stable, homogeneous liquid dispersions.
These and other objects are obtained herein as will be seen from the following disclosure.